2013-02-11 According to a Lockheed Martin Press Release:
EDWARDS AIR FORCE BASE, Calif., Feb 11, 2013
An F-35A Lightning II conventional takeoff and landing aircraft, known as AF-1, completed its final test mission for clean wing flutter recently.
Flutter testing was conducted to ensure the jet’s structure could withstand various aerodynamic loads verifying the F-35A’s design.
The mission, flown by Maj. Ryan “Gunner” Reinhardt, marks the conclusion of three years of testing that now allows the F-35A to proceed with tests continuing to expand its flight envelope and validate predictions in real-world scenarios.
The testing demonstrated the F-35 is clear of flutter, at speeds up to 1.6 Mach and 700 knots with weapon bay doors open or closed, critical to performing its combat mission.
Data collected proves the F-35A flight dynamics maintains a large margin between its designed airspeed and airspeeds where possible flutter could occur.
(Lockheed Martin photo by Matt Short.)